; *******************************************************************
; Polydefix stress, strain, and texture analysis for experiment in 
; angle dispersive geometry
; Copyright (C) 2000-2011 S. Merkel, Universite Lille 1
; http://merkel.zoneo.net/Multifit/
; 
; This program is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version 2
; of the License, or (at your option) any later version.
; 
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
;
; *******************************************************************

function latticestrain, x, A
cosx = cos(x)
d = A[0]*(1.+A[1]*(1.-3.*cosx*cosx))
return, d
end
